While signal conditioning techniques for resistive sensors based on the Wheatstone bridge (WB) circuit are widely used, a Wheatstone bridge configuration may not facilitate achieving low-voltage and low power consumption characteristics.
The sensitivity of a Wheatstone bridge may in fact be of the order of few mV/V (output voltage/excitation voltage), and high excitation voltages and amplification plus filtering stages may be used in order to enhance the signals to the proper input dynamic range of analog to digital converters. This may introduce noise, nonlinearities and increase the overall power consumption.
Moreover, current consumption of a Wheatstone bridge may be high (for example, in the order of mA or higher) and cannot be easily reduced by designing high-resistive sensors, insofar as the resistance of resistive sensors depend on the physical characteristics of the sensor and the physical environment to be measured.
There is a need in the art to dispense with the drawbacks outlined in the foregoing.